ngin - Norfolk Genetic Information Network

4 February 2002


Regarding item 3, it's surely come to something when even the Royal Society is sounding more cautious than our great CONsumer watchdog: the Food Standards Agency. Time for Krebs and Patterson to go!

1. GM crops may become weedier - EN
3. RS: GM food safety checks inadequate - New Scientist


1. GM crops may become weedier


An extensive study commissioned by English Nature* of GM herbicide tolerant oilseed rape crops in Canada has revealed that genes from separate GM varieties can accumulate ('gene stacking') in plants that grow from seed spilled at harvest (volunteer plants).  This happens because different varieties cross-pollinate, and their offspring may contain the accumulated genes from GM varieties with different genetic traits.  In Canada these plants are now resistant to several widely used herbicides, with farmers regularly resorting to old herbicides to control them.  In effect they are on the road to becoming nuisance weeds.

The Canadian system of voluntary guidelines advising farmers to leave a separation distance of 175 m between different GM varieties seems to have broken down, and 'gene stacking' is now widespread in Canada. A code of practice for farmers growing GM crops in the UK has already been developed by the industry body SCIMAC.

Dr Brian Johnson, English Nature's biotechnology advisor said today: "Our report shows that the SCIMAC code is probably inadequate to prevent gene stacking happening in Britain, if these crops were commercialised.  The consequences for farmers could be that volunteer crops would be harder to control and they might have to use different, and more environmentally damaging, herbicides to control them."

English Nature are concerned that attempts to eliminate GM volunteers with multiple herbicide tolerance in 'weedy' crops like oilseed rape could lead to more intensive herbicide use in field margins and uncropped habitats, which can be important refuges for wildlife.

Dr Johnson said: "We do not yet know how 'stacked gene' plants would behave either in farmers' fields or in the wild. The European regulatory system has not yet approved GM herbicide tolerant oilseeds for general release. English Nature will be working with DEFRA and ACRE to ensure that risks from possible gene stacking are properly addressed, and that we avoid the mistakes that have been made in Canada".

The European Commission has recently proposed that a threshold of up to 0.7% GM seed should be allowed in batches of conventional crop seed.  English Nature are deeply concerned that if this proposal were to be adopted, it might be a recipe for gene stacking, because the GM plants from a seed batch could be made up of several varieties that would inevitably hybridise, giving 'volunteer' plants next season with multiple GM traits.  It will be difficult to police seed batches to ensure that this does not happen.

English Nature has been pressing the GM industry to explain how to deal with these issues before GM crops are released widely, rather than wait for stacking to emerge and then try to control the rogue crop plants.


Notes for Editors

1.  On this issue, English Nature is the lead agency for the UK statutory nature conservation agencies which are English Nature, Scottish Natural Heritage, The Countryside Council for Wales and the Joint Nature Conservation Committee.

2. The study, Gene-stacking in herbicide-tolerant oilseed rape: lessons from the North American experience, English Nature research report Number 443, was undertaken by Jim Orson, director of Morley Research Centre, on behalf of English Nature.  Embaroged copies are available from English Nature's national Press Office and will be on the web site
on 5 February 2002.

3. 'Volunteer' crop plants are those that grow from seed left on the ground after harvest.  They germinate and (unless they are controlled by cultivation and herbicides) can appear in following crops, field margins and roadside verges.

Gene stacking is where cross-pollination results in genes from different GM varieties occurring together in individual 'volunteer' plants that grow from seed left behind during harvesting.  Some volunteer oilseed rape (canola) plants in Canada have three herbicide tolerance genes within them, making them resistant to some of the most commonly used agricultural herbicides.

ACRE is the Advisory Committee on Releases to the Environment.  ACRE is an independent committee that advises ministers on whether consent should be given to release GMOs into the environment.

SCIMAC is the Supply Chain Initiative for Modified Agricultural Crops, an industry sponsored group that has produced guidelines for growers intending to use GM crops.

4. The SCIMAC Code of Practice, published in 1999, recommends a separation distance of 50m for GM oilseed rape.

5. A copy of the EC working paper on adventitious presence of GM seeds in seed of conventional plant varieties is available at
The opinion of the EC Scientific Committee on Plants, which advises the Commission, is that the proposed thresholds of GM presence in non-GM seed will be difficult, if not impossible, to achieve, particularly as the global area of GM crops continues to grow. The opinion is published at

6. For more information: English Nature's National Press Office 01733 455190 out-of-hours 07970 098005 email or visit our website at



Embargo: 00:01 Tues 5 February 2001

Super weeds, resistant to a number of herbicides, are already resulting from growing  genetically modified crops, a new report from the UK Government's nature watchdog warns today. The findings will increase fears about the threat posed by GM crop trials growing in the UK to neighbouring crops and the environment.

English Nature carried out research into a herbicide-tolerant oilseed rape crop in Canada. It discovered that "genes from separate GM varieties can accumulate ('gene stacking') in plants that grow from seed spilled at harvest (volunteer plants)...these plants are now resistant to several widely used herbicides, with farmers regularly resorting to old herbicides to control them" . This may lead farmers "to use different, and more environmentally damaging, herbicides to control them".

English Nature is also concerned that:

. the GM industry's planned separation distances for commercially grown GM crops in the UK are "probably inadequate to prevent gene stacking happening in Britain"
. the European Commission proposal that a threshold of 0.7 % GM seed should be allowed in batches of conventional crop seed would be a recipe for gene stacking.

Last week Friends of the Earth attacked the Government for allowing a new round of GM oilseed rape trials to proceed with inadequate separation distances. FOE estimates that neighbouring conventional and organic crops within a three mile radius are under threat from GM contamination. Separation distances between GM oilseed rape trials and conventional varieties are currently 50 metres.

Adrian Bebb, GM Campaigner at Friends of the Earth said "English Nature's vital research shows that we now face a stark choice. Either we keep the current separation distances between GM and non-GM crops, in which case contamination and gene stacking looks certain. Or we can have an effective separation distance - of at least three miles - in which case GM crops have no commercial future in the UK. There is no third way

The Government must choose between continuing its support for the biotech industry or backing the British public who have clearly said they don't want GMOs."

Adrian Bebb 07712 843 211 (mob)


3. GM food safety checks inadequate, says report

RS report - download as pdf:
GM food safety checks inadequate, says report
New Scientist
04 February 02
James Randerson

The way genetically-modified food is tested for safety in Europe must be improved before any new GM plants are declared fit for human consumption, according to a report by the Royal Society, the UK's foremost scientific society.

"The battery of tests should be spelt out much more clearly," says Eric Brunner at University College London and one of the authors of the report. Some animal testing may also be required, he says.

The testing regime must be independently scrutinised, recommends the report, so that companies cannot submit selective data about their new GM products. Otherwise, Brunner says: "Companies could carry on generating data until they get the answer they want."

However, the report concludes that there is no reason to doubt the safety of foods made from GM ingredients that are currently available, nor to believe that genetic modification makes foods inherently less safe than their conventional counterparts.

The UK Food Standards Agency welcomed the report but said it was "satisfied that the current safety assessment procedures are sufficiently robust and rigorous to ensure that approved GM foods are as safe as their non-GM counterparts".

Adrian Bebb of Friends of the Earth believes that the report will add to public scepticism about GM foods. "It confirms the public's suspicions," he says. "But the report leaves lots of questions unanswered."

Blunt instrument

At present, companies must demonstrate that a GM product is 'substantially equivalent' to its conventional version. This is a less rigorous standard than used, for example, in testing new drugs. But the report accepts that using such standards for foods would be impractical, given the complexity of foodstuffs. Also, many traditional foods would fail such tests.

The equivalence test compares, for example, protein, carbohydrate and fatty acid levels between the GM and non-GM plants. But there are no clear and universal guidelines over exactly what to test and how similar the two should be. Brunner says different interpretations of the regulations by different countries might leave a regulatory 'back door': "One country should not be used as a fast route into the EU market."

Such differences of interpretation are already apparent between the EU and the US. For example all products from a herbicide resistant variety of GM oilseed rape developed by Aventis were approved in the US. In the EU, only the processed oil was deemed safe.

"Substantial equivalence is a very blunt instrument," says Brunner. "It is a flawed concept if used on its own." Animal testing may be needed to explore particular safety aspects of a new food, he adds.

Allergic reaction

While the report's authors were sceptical about current testing arrangements, they saw no reason to believe that current GM varieties are unsafe. They argue that if were they dangerous, problems would have emerged during widespread consumption in the US.

Bebb counters that there has been no post-market monitoring of the long-term health effects of GM ingredients. So problems caused by the foods might have been missed.

They also quash fears that engineered genes could incorporate into the human genome via the gut. We eat DNA in our food all the time without any such problems, says Jim Smith, chairman of the Wellcome Cancer Research Campaign Institute in Cambridge, who chaired the report.

But the report does recommend that all new foods be tested to see if they cause allergic reactions when particles are inhaled. GM foods are no more likely to trigger such allergies than conventional crops, the report says, but they say that current regulation would miss these lung allergies.

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